BitmapData.Scan0 Property

 

Gets or sets the address of the first pixel data in the bitmap. This can also be thought of as the first scan line in the bitmap.

Namespace:   System.Drawing.Imaging
Assembly:  System.Drawing (in System.Drawing.dll)

public IntPtr Scan0 { get; set; }

Property Value

Type: System.IntPtr

The address of the first pixel data in the bitmap.

The following code example demonstrates how to use the PixelFormat, Height, Width, and Scan0 properties; the LockBits and UnlockBits methods; and the ImageLockMode enumeration. This example is designed to be used with Windows Forms. To run this example, paste it into a form and handle the form's Paint event by calling the LockUnlockBitsExample method, passing e as PaintEventArgs.

System_CAPS_noteNote

The following example code was created for use with an image with the Format24bppRgb format.

    private void LockUnlockBitsExample(PaintEventArgs e)
        {

            // Create a new bitmap.
            Bitmap bmp = new Bitmap("c:\\fakePhoto.jpg");

            // Lock the bitmap's bits.  
            Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height);
            System.Drawing.Imaging.BitmapData bmpData =
                bmp.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite,
                bmp.PixelFormat);

            // Get the address of the first line.
            IntPtr ptr = bmpData.Scan0;

            // Declare an array to hold the bytes of the bitmap.
            int bytes  = Math.Abs(bmpData.Stride) * bmp.Height;
���         byte[] rgbValues = new byte[bytes];

            // Copy the RGB values into the array.
            System.Runtime.InteropServices.Marshal.Copy(ptr, rgbValues, 0, bytes);

            // Set every third value to 255. A 24bpp bitmap will look red.  
            for (int counter = 2; counter < rgbValues.Length; counter += 3)
                rgbValues[counter] = 255;

            // Copy the RGB values back to the bitmap
            System.Runtime.InteropServices.Marshal.Copy(rgbValues, 0, ptr, bytes);

            // Unlock the bits.
            bmp.UnlockBits(bmpData);

            // Draw the modified image.
            e.Graphics.DrawImage(bmp, 0, 150);

        }

.NET Framework
Available since 1.1
Return to top
Show: